1. Field of the Invention
The present invention relates to an analyzer configured to be installed on a moving body (vehicle) for analyzing motion of the moving body.
2. Description of the Related Art
Aiming at preventing traffic accidents, driving support systems using a stereo camera or a radar are actively studied nowadays. A driving support system installed on a vehicle searches for obstacles existing in a moving direction of the vehicle. Upon detecting an obstacle, the system measures the distance to the obstacle, judges whether the obstacle is threatening the vehicle, and if so, produces a warning to a driver or actuates brakes in a controlled fashion. The driving support system also analyzes relative motion of the vehicle and the obstacle. This analysis could provide information on driving habits, or personal behavior, of the driver, and results of the analysis may be effectively used for cautioning the driver or for reeducating the driver. Another possible application of the driving support system would be to use the same for scrutinizing vehicle motion in a traffic accident by analyzing images recorded by a so-called drive recorder.
In particular, the driving support system combined with a stereo camera offers a remarkable advantage which the driving support system combined with a radar can not offer in that the former makes it possible to identify the obstacle by processing recorded images.
Japanese Unexamined Patent Publication No. 2006-53755 proposes a technique for determining a distance traveled by a vehicle by determining road surface parameters from stereo images, producing time-sequential bird's eye views and matching the obtained bird's eye views with standard or reference images. A non-patent document, entitled “Understanding Images—Mathematical Principle of 3D Recognition,” K. Kanaya, par. 5. Three-dimensional Analysis of 3-plane Optical Flow, p 123, introduces a technique for analyzing motion of a moving body without working out three-dimensional information but with the need for plan-view area information to be given in advance.
The technique of the aforementioned Patent Publication calculates the traveled distance by producing bird's eye views, and a later-described processing method of the present invention completely differs from this conventional approach of the Publication. Also, the technique of the aforementioned non-patent document calculates motion parameters without using any three-dimensional information, so that it is difficult to estimate the traveled distance with high accuracy.